Human Nature Part II: Learning, Memoy, Imagination

By Liah Greenfeld

As I argued in my previous post, in contrast to all other animals who transmit their ways of life genetically, i.e., through their genes and genetic capacities which humans as animals share, humans transmit their ways of life symbolically, i.e., through culture. Culture is irreducible to such genetic capacities, but it could not exist without them. Therefore, to understand the specificity of culture as the distinguishing characteristic of humanity, we must first establish what it is not and discuss these animal capacities which are often confused with culture.

The most important of these capacities, which form necessary, but not sufficient, conditions for culture, have to do with the biological mechanisms enabling the individual animal to recognize (i.e., interpret) new signs, that is signs which are not genetically encoded, and quickly acquire the ability to read them in an environment of any complexity. The more complex the environment the more important are these skills, which neuroscientists call “learning” and “memory,” for the survival of the animal. The highly developed animal brain, adapted to the very complex environments in which most birds and mammals live, is highly capable of learning and memory. We humans, as animals, share these evolutionarily produced capacities of the animal brain with other animals.

The cognitive processes involved in learning and memory are far more complicated than they appear at first sight and than the words “learning” and “memory,” as used in neuroscience, suggest. “Learning,” connoting a process common to a primitive organism such as the sea-slug Aplysia (which has been the focus of some very important research in the neuroscience of learning) and humanity, is used in neuroscience in the sense of experience of contact with the environment. But, clearly, the ability to recognize new signs involves much more than such an experience. To begin with, it involves a comparison—usually, a series of comparisons—with the already known signs.

For instance, a lion cub knows that the sight of an approaching buffalo means danger which requires that the cub run away or hide. The smell of an approaching buffalo also means that. Then the cub experiences an approaching Land Rover. Its sight is quite similar to the buffalo: it is big, dark, it is moving swiftly, trampling everything on its path. The smell of the “Land-Rover,” however, is very different from that of a buffalo or of any living thing the lion cub knows genetically. Does it signify danger too? Should the cub run and hide? The lion cub hides, but his companion, another cub, does not. The Land Rover stops and appears completely uninterested in pursuing and harming the cub who did not hide. An unusual looking living thing (judging by the smell) emerges out of its belly, looks at the cub and, moving its paws unthreateningly, lifts and holds to its face an object. The cub concludes that a buffalo-resembling thing that is not alive with a living thing looking like no other living thing in it, while certainly a sign of curiosity, is not necessarily a sign of danger. But he is a very intelligent cub, who is suspicious of generalizing from one instance. Next time he and his less suspicious companion encounter a moving Land Rover, our cub still hides. The big dark thing stops, a strange living creature appears, lifts an object which makes loud noise, and the trusting friend of the cub falls dead. It did not take time to consider the new sign. The intelligent lion cub makes a further comparison: the object in the paws of the living thing, which killed its hapless playmate, looked and smelled different from the object the living thing held to its face on the previous occasion. It concludes: guns kill, cameras don’t; a moving Land Rover signifies danger unless proven harmless by the absence of a gun in the living thing’s paws.

“Learning” thus consists not simply in perceiving the unfamiliar environmental stimulus, but in analyzing it in comparison with what the animal knows already (from previous learning experiences or from the genetically encoded information). And it is the lesson learned through this analysis that the organism then records in its “memory.”

Neuroscientists use the term “memory” in the sense of a record of the organism’s contacts with the environment. This record can be declarative or non-declarative and can represent numerous aspects of the contact that is recorded: visual, spatial, temporal, emotional, olfactory, audial, tactile, etc.—i.e. it can preserve whichever aspect of the contact was perceived, that is sensed, captured by the nervous system. What is recorded, however, is the learning experience, which, in addition to perception, involves its analysis and interpretation, a cognitive, intellectual procedure performed by the brain with the information available to it, some of it newly acquired, some genetically encoded, and some already stored in memory. And it is this experience, part experience of a contact with the environment, part that of reprocessing and manipulation of already known information that is recorded in memory.

In a well-known experiment Dusek and Eichenbaum have taught a sample of healthy rats a number of associations with odors presented in different sequences and established that rats are capable of nothing less than transitive inference—namely drawing valid logical conclusions from a set of premises, a mental procedure represented in the form of “categorical syllogism.” The animals are first trained to recognize patterns of sequential pairing of odors which can be called A-B and X-Y.  Trials after this training present the rats with an initial odor A and the option of choosing between odors B or Y.  The correct choice, based on the cue of odor A would be to choose its pair of odor B and thus garner a reward for the animal (a fruit loop)—if the initial cue is odor X then the correct choice out of options B or Y would be Y.  The pair associations are then expanded by the introduction of odor pairs B-C and Y-Z and then tested in the same way.  In a third testing trial, all the rats responded correctly to a novel pair sequence where the cue and the choices were only indirectly associated (i.e. A and C or X and Z) thus exhibiting the capacity for transitive inference, or for the interleaving of stimuli based on associative relationships.

This intellectual performance is not different from a person “figuring out” the principle uniting a series of perceptually dissimilar objects into a category, as one frequently has to do in IQ tests or, in a far more complex case, of a child figuring out the principles of the mother-tongue. The cue for the rats’ astonishing behavior is not a part of the sensorily perceived features of the environment with which the organism was in contact. The inference that “if A leads to B, and if B leads to C, then A leads to C” is not information supplied by the environment—the clever rodents create it inside their brains; they guess, or imagine that this is so. When we say, in the human context, of simple syllogisms such as the one above, that the conclusion is “contained” in the premises, we use the word “contained” metaphorically, meaning that anyone with enough intelligence to recognize that the two propositions have the same middle term, will envision the conclusion in the premises. But not everybody does see the conclusion in the premises: they need to perform some mental work to put it there first.

The ability of an animal to adapt to a complex environment and react appropriately to new stimuli within it, therefore, in addition to perception and committing to memory of information offered by the environment, depends on the mental process of creating supplementary information inside the organism. Such creativity, the ability to complete within the brain the information received from outside by adding to it the unknown information necessary for adaptation is not recognized among animals and therefore goes without a name. In humans, we call the ability to do so imagination. Clearly, animals are capable of it at least to the extent required by the complexity and indeterminacy of their environment.

The native intelligence, learning ability, and the creative imaginative capacity of some animals well may be as or better developed than those of humans, but these innate capacities do not create culture. In the next post, we’ll see why.

[Originally published on Psychology Today]

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